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Tempei Hashino and Gregory J. Tripoli

cloud-resolving models (CRMs), particle properties of crystals and aggregates are typically assigned by categories, given the computational cost and the uncertainties associated with a lack of physical understanding. The variability of aggregation processes resulting from particle history or habits is directly related to the number of assumed categories. Thus, this approach is not ideal to study the variability. The simulation of habits and sizes is particularly important in association with the

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Christopher M. Rozoff, James P. Kossin, Wayne H. Schubert, and Pedro J. Mulero

of the synoptic-scale storm environment. This is not the case, however, and it is fairly typical for storms to strengthen or weaken, sometimes rapidly, without any clear commensurate changes in the storm environment. Although the specific processes involved remain an open question, this behavior is widely believed to result from internal mesoscale processes that can have a profound effect on how storm intensity evolves. This implies that the ability to model and ultimately predict hurricane

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Alvaro Semedo, Øyvind Saetra, Anna Rutgersson, Kimmo K. Kahma, and Heidi Pettersson

wind profile over the ocean, under swell conditions, is no longer logarithmic makes the correct evaluation of the roughness length a cumbersome problem (see Figs. 3 and 7 in Smedman et al. 2003 ). For the model sensitivity tests to roughness length variations, several formulations are used ( Table 1 ). Once again the original profile evaluated with z 0 = 10 −5 m is kept as a reference and is shown as a solid line in Fig. 7 . The profiles corresponding to several roughness lengths from the

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Yuxuan Wang, Yuanyu Xie, Libao Cai, Wenhao Dong, Qianqian Zhang, and Lin Zhang

observations and the GEOS-Chem model used in the study, with a focus on drought-induced variations of natural emissions simulated by the model. In section 4 we analyze the observed changes of PM 2.5 and its major components under drought conditions and evaluate the model’s ability in reproducing those observed changes. In sections 5 and 6 , the drought’s impact on important PM 2.5 components including OC and sulfate are quantified through budget analysis. Discussion and conclusion are given in

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Robert Wood, Terence L. Kubar, and Dennis L. Hartmann

d ) 1.75 . Figure 1 shows lines of constant LWP/ N d and LWP 2 / N d , which span the observed range of sensitivity. Both the SS model and CC model isohyets for the region of (LWP, N d ) phase space to which they apply are broadly consistent with the closure studies. Unfortunately, no closure studies exist with which to evaluate the dependencies at higher precipitation rates associated with deeper marine low clouds. Extensive details regarding the CloudSat /MODIS observations and their

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George H. Bryan and Richard Rotunno

analytical model of Emanuel (1986 , hereafter E86) . The purpose of this article is to investigate the source of this discrepancy. To this end, we evaluate the underlying assumptions of Emanuel’s potential intensity theory (E-PI; E86 ) using output from numerical model simulations in which steady tropical cyclone intensity greatly exceeds E-PI. The same methodology was undertaken by PM03 . They ultimately concluded that the underlying thermodynamic assumption in E-PI (moist slantwise neutrality) was

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Gwendal Rivière

–contraction process (called hereafter the barotropic regeneration process) takes place preferentially east of the mountains in a confluent region or north of the subtropical jets. It is worth noting that this process is a transient nonmodal phenomenon that may occur without the presence of barotropic instability, as shown theoretically in simple linear barotropic models by Farrell (1989) and Lee (1995) . The transition from elongation to contraction stages requires a rapid change of the environment in which

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Maurizio Fantini and Piero Malguzzi

light-thermodynamics environment, the argument given above can be modified to show that neutral buoyancy ( T p υ ) f = ( T e υ ) f coincides with the tangent to θ * e contours. Given a numerical model and environmental thermodynamic quantities, the direction of neutral buoyancy can be obtained numerically by letting the model evaluate the parcel virtual temperature T p υ ( p + Δ p ) after a displacement Δ p , and then solving for (Δ x , Δ z ) the following system: In the cases in which we

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Xiouhua Fu, Bin Wang, Duane E. Waliser, and Li Tao

, M. Newman , J. D. Glick , and J. E. Schemm , 2000 : Medium-range forecast errors associated with active episodes of the Madden–Julian oscillation. Mon. Wea. Rev. , 128 , 69 – 86 . Hollingsworth , A. , K. Arpe , M. Tiedtke , M. Capaldo , and H. Savijarvi , 1980 : The performance of a medium-range forecast model in winter—Impact of physical parameterizations. Mon. Wea. Rev. , 108 , 1736 – 1773 . IFRC , 2000 : World Disaster Report: Focus on Recovery . IFRC, 392

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Gang Chen and Pablo Zurita-Gotor

Global Atmospheric Model Development Team , 2004 : The new GFDL global atmosphere and land model AM2/LM2: Evaluation with prescribed SST simulations. J. Climate , 17 , 4641 – 4673 . Haigh , J. D. , M. Blackburn , and R. Day , 2005 : The response of tropospheric circulation to perturbations in lower-stratospheric temperature. J. Climate , 18 , 3672 – 3685 . Hartmann , D. L. , and P. Zuercher , 1998 : Response of baroclinic life cycles to barotropic shear. J. Atmos. Sci

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